Visual Analogue Scale: Difference between revisions

No edit summary
No edit summary
Line 33: Line 33:
Recall period for items.Varies, but most commonly respondents are asked to report “current” pain intensity or pain intensity “in the last 24 hours.”  
Recall period for items.Varies, but most commonly respondents are asked to report “current” pain intensity or pain intensity “in the last 24 hours.”  


== Scoring and Interpretation ==
== Scoring and Interpretation ==


Using a ruler, the score is determined by mea-suring the distance (mm) on the 10-cm line between the “no pain” anchor and the patient’s mark, providing a range of scores from 0–100. A higher score indicates greater<br>pain intensity. Based on the distribution of pain VAS scores in post- surgical patients (knee replacement, hyster-ectomy, or laparoscopic myomectomy) who described their postoperative pain intensity as none, mild, moderate, or severe, the following cut points on the pain VAS have&nbsp;been recommended: no pain (0–4 mm), mild pain(5-44 mm), moderate pain (45–74 mm), and severe pain (75–<br>100 mm) (11). Normative values are not available.
Using a ruler, the score is determined by mea-suring the distance (mm) on the 10-cm line between the “no pain” anchor and the patient’s mark, providing a range of scores from 0–100. A higher score indicates greater<br>pain intensity. Based on the distribution of pain VAS scores in post- surgical patients (knee replacement, hyster-ectomy, or laparoscopic myomectomy) who described their postoperative pain intensity as none, mild, moderate, or severe, the following cut points on the pain VAS have&nbsp;been recommended: no pain (0–4 mm), mild pain(5-44 mm), moderate pain (45–74 mm), and severe pain (75–<br>100 mm) (11). Normative values are not available.  


== Merits and Demerits  ==
== Merits and Demerits  ==
Line 41: Line 41:
*VAS is more sensitive to small changes than are simple descriptive ordinal scales in which symptoms are rated,for example, as mild or slight,moderate,or severe to agonizing.  
*VAS is more sensitive to small changes than are simple descriptive ordinal scales in which symptoms are rated,for example, as mild or slight,moderate,or severe to agonizing.  
*These scales are of most value when looking at change within individuals  
*These scales are of most value when looking at change within individuals  
*The VAS takes�1 minute to complete
*The VAS takes�1 minute to complete  
*No training is required other than the ability to use a ruler to measure distance to determine a score
*No training is required other than the ability to use a ruler to measure distance to determine a score  
*However, assessment is clearly highly subjective  
*Minimal translation difficul-ties have led to an unknown number of cross-cultural adaptations<br>
**However, assessment is clearly highly subjective  
*Are of less value for comparing across a group of individuals at one time point.  
*Are of less value for comparing across a group of individuals at one time point.  
*It could be argued that a VAS is trying to produce interval/ratio data out of subjective values that are at best ordinal.  
*It could be argued that a VAS is trying to produce interval/ratio data out of subjective values that are at best ordinal.  
*The VAS is administered as a paper and pencil measure. As a result, it cannot be admin-istered verbally or by phone.
*The VAS is administered as a paper and pencil measure. As a result, it cannot be admin-istered verbally or by phone.  
*Caution is required when photo-copying the scale as this may change the length of the 10-cm line
*Caution is required when photo-copying the scale as this may change the length of the 10-cm line and also,&nbsp;the same alignment of scale should be used consistently within the same<br>patient


Thus, some caution is required in handling such data.&nbsp;<ref name="cebp" />  
Thus, some caution is required in handling such data.&nbsp;<ref name="cebp" />  


== Obtaining the scale ==
== Obtaining the scale ==


<span>&nbsp;The pain VAS is available in the public domain at no cost. Graphic formats for the VAS may be obtained from Scott &amp; Huskisson or online: http:// www.amda.com/tools/library/whitepapers/hospiceinltc/ appendix-a.pdf.</span>&nbsp;
<span>&nbsp;The pain VAS is available in the public domain at no cost. Graphic formats for the VAS may be obtained from Scott &amp; Huskisson or online: http:// www.amda.com/tools/library/whitepapers/hospiceinltc/ appendix-a.pdf.</span>&nbsp;  


== References  ==
== References  ==

Revision as of 22:02, 16 March 2014

Introduction[edit | edit source]

A Visual Analogue Scale (VAS) is a measurement instrument that tries to measure a characteristic or attitude that is believed to range across a continuum of values and cannot easily be directly measured[1]. It is often used in epidemiologic and clinical research to measure the intensity or frequency of various symptoms.Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title For example, the amount of pain that a patient feels ranges across a continuum from none to an extreme amount of pain.[1] From the patient's perspective this spectrum appears continuous ± their pain does not take discrete jumps, as a categorization of none, mild, moderate and severe would suggest. It was to capture this idea of an underlying continuum that the VAS was devised.[1]

Purpose[edit | edit source]

The pain VAS is a unidimensional measure of pain intensity, which has been widely used in diverse adult populations, including those with rheumatic diseases.[2] [3] [4] [5] [6]

Structure,Orientation and Response Options[edit | edit source]

VAS can be presented in a number of ways,including:

  • scales with a middle point,graduations or numbers (numerical rating scales),
  • meter-shaped scales (curvilinear analogue scales),
  • "box-scales,"scales consisting of circles equidistant from each other(one of which the subject has to mark),and
  • scales with descriptive terms at intervals along a line (graphic rating scales or Likert scales) Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title
  • The most simple VAS is a straight horizontal line of fixed length, usually 100 mm. The ends are defined as the extreme limits of the parameter to be measured (symptom,pain,health)Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title orientated from the left (worst) to the right (best). In some studies,horizontal scales are orientated from right to left ,and many investigators use vertical VASCite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title.
  • No difference between horizontal and vertical VAS has been shown in a survey involving 100 subjectsCite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title but other authors have suggested that the two orientations differ with regard to the number of possible angles of viewCite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title. Reproducibility has been shown to vary along a vertical 100-mm VAS and along a horizontal VAS Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title. The choice of terms to define the anchors of a scale has also been described as important.Cite error: Invalid <ref> tag; name cannot be a simple integer. Use a descriptive title

Administration[edit | edit source]

  • They are generally completed by patients themselves but are sometimes used to elicit opinions from health professionals.
  • The patient marks on the line the point that they feel represents their perception of their current state.
  • The VAS score is determined by measuring in millimetres from the left hand end of the line to the point that the patient marks.[1]

Recall Period for items[edit | edit source]

Recall period for items.Varies, but most commonly respondents are asked to report “current” pain intensity or pain intensity “in the last 24 hours.”

Scoring and Interpretation[edit | edit source]

Using a ruler, the score is determined by mea-suring the distance (mm) on the 10-cm line between the “no pain” anchor and the patient’s mark, providing a range of scores from 0–100. A higher score indicates greater
pain intensity. Based on the distribution of pain VAS scores in post- surgical patients (knee replacement, hyster-ectomy, or laparoscopic myomectomy) who described their postoperative pain intensity as none, mild, moderate, or severe, the following cut points on the pain VAS have been recommended: no pain (0–4 mm), mild pain(5-44 mm), moderate pain (45–74 mm), and severe pain (75–
100 mm) (11). Normative values are not available.

Merits and Demerits[edit | edit source]

  • VAS is more sensitive to small changes than are simple descriptive ordinal scales in which symptoms are rated,for example, as mild or slight,moderate,or severe to agonizing.
  • These scales are of most value when looking at change within individuals
  • The VAS takes�1 minute to complete
  • No training is required other than the ability to use a ruler to measure distance to determine a score
  • Minimal translation difficul-ties have led to an unknown number of cross-cultural adaptations
    • However, assessment is clearly highly subjective
  • Are of less value for comparing across a group of individuals at one time point.
  • It could be argued that a VAS is trying to produce interval/ratio data out of subjective values that are at best ordinal.
  • The VAS is administered as a paper and pencil measure. As a result, it cannot be admin-istered verbally or by phone.
  • Caution is required when photo-copying the scale as this may change the length of the 10-cm line and also, the same alignment of scale should be used consistently within the same
    patient

Thus, some caution is required in handling such data. [1]

Obtaining the scale[edit | edit source]

 The pain VAS is available in the public domain at no cost. Graphic formats for the VAS may be obtained from Scott & Huskisson or online: http:// www.amda.com/tools/library/whitepapers/hospiceinltc/ appendix-a.pdf. 

References[edit | edit source]

  1. 1.0 1.1 1.2 1.3 1.4 D. Gould et al. Visual Analogue Scale (VAS). Journal of Clinical Nursing 2001; 10:697-706
  2. Mc Cormack HM, Horne DJ, Sheather S. Clinical applications of visual analogue scales: a critical review. Psychol Med 1988;18:1007–19.
  3. Huskisson EC. Measurement of pain. Lancet 1974;2:1127–31.
  4. Downie WW, Leatham PA, Rhind VM, Wright V, Branco JA, Anderson JA. Studies with pain rating scales. Ann Rheum Dis 1978;37:378–81.
  5. Huskisson EC, Wojtulewski JA, Berry H, Scott J, Hart FD, Balme HW. Treatment of rheumatoid arthritis with fenoprofen: comparison with aspirin. Br Med J 1974;1:176–80.
  6. Berry H, Huskisson EC. Treatment of rheumatoid arthritis. Clin Trials J 1972;4:13–5